油基钻井液用提切剂的研制及性能评价

Synthesis and properties of a rheological modifier for oil based drilling fluid

油基钻井液为页岩气井、高温高压井和复杂井的首选。但相较于水基钻井液,油基钻井液的流变性更难以控制,国内适应的处理剂也很缺乏。笔者以苯乙烯、甲基丙烯酸甲酯和丙烯酸十六酯为单体,通过悬浮聚合法合成一种亲油共聚物提切剂。利用红外光谱仪(FT-IR)对其化学结构进行表征,热重分析仪(TGA)分析其热稳定性能并评价了其在油基钻井液中的性能。结果表明,该聚合物提切剂具有良好的热稳定性,加入该聚合物的柴油基钻井液切力大幅上升,高温高压滤失量显著下降,较好地改善了泥饼质量,且不影响钻井液体系的稳定性,是一种很好的增黏提切材料。

Oil based drilling fluid for shale gas well,HTHP well and complicated well,becomes more and more popular in China. However,compared with water based drilling fluid,the rheological property of oil based drilling fluid is more difficult to control and the adaptable treating agents are less at present. In this study,a copolymer rheological modifier is synthesized by suspension polymerization with styrene,methyl methacrylate and hexadecyl acrylate as monomer. The obtained copolymer is characterized by FT-IR and TGA,and the properties of drilling fluids are evaluated before and after application. The results show that the copolymer possesses desirable thermal resistant property,largely raised shear stress,obviously reduced HTHP filtration and greatly improved mud cake property. This polymer does not affect the stability of the drilling fluid and is a commendable rheological modifier for oil based drilling fluid.